Articulated two wheel board

ABSTRACT

A two wheel articulated board device which the user can operate on smooth rough or smooth terrain. The device has a rear board member and a front board member which are connected at a pivot point. Each board member can rotate relative to the other board member around this pivot point. The device is supported by two wheels. A rear wheel which extends rear of the board and above the level of the board and a front wheel which extends forward of the board and above the level of the board. The front wheel is connected to the board by a front fork which attaches to the underside of the board. The rear wheel is connected to the board by a rear fork which attaches to the underside of the board. There is a flexible member that connects at one end with the underside of the device rear of the pivot point and at the other end at the underside of the device forward of the pivot point. The user motions the board forward by placing one foot on the rear board member with that foot oriented about 45 degrees off the major axis of the device. Forward motion is achieved by the user pushing against the ground with his/her other foot. Once the user has gained enough speed and begins coasting, the user repositions his/her feet perpendicular to the long axis of the device. While coasting the user can affect a change of direction by changing the relative orientation of his/her feet which are initially parallel without lifting them off the device. Moving the user&#39;s feet by bringing his/her toes closer together causes the rear board member to move relative to the front board member around the pivot point and thus affects a change of direction of the device. A flexible member running under the device along the major axis of the device and connected at one end to the rear board member and at the other end to the front board member applies a force to keep each board member aligned along their respective major axes.

FIELD OF THE INVENTION

The present invention relates to board based recreational devices likeskateboards and mountain boards.

BACKGROUND OF THE INVENTION

There are many types of board based recreational devices. These includeskateboards with four wheels for operation on pavement; mountain boardswith four wheels for operation on rough terrain and inline skateboardsfor operation on pavement.

The prior art includes a plurality of mountain boards with four wheelsthat extend above the level of the board. For example, U.S. Pat. No.5,794,955 describes such a four wheel mountain board.

The prior art includes U.S. Pat. No. 5,160,155 which discloses askateboard having two wheels in tandem. This patent also discloses aspring based mechanism for dampening and centering the front steeringwheel. The front steering wheel is positioned rear of the point of pivotbetween the wheel and the skateboard.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an articulated twowheel board device for operation on rough and smooth terrain.

It is a more particular object of the invention to provide a board thatis made up of two sections, the front board member and the rear boardmember.

It is another object of the invention to provide a pivot point where thefront board member connects to the rear board member.

It is another object of the invention to provide a rear wheel thatextends behind the rear board member and above the level of the rearboard member and attached to the rear board member. It is another objectof the present invention to provide a front wheel that extends in frontof the front board member and above the level of the front board memberand attached to the front board member.

Preferably the front wheel is connected to the front board member bymeans of a front fork member which attaches to the front wheel axle.

Preferably the rear wheel is connected to the rear board member at therear pivot point by means of a rear fork which attaches to the rearwheel axle.

It is another object of the invention to provide the pivot point whichincludes thrust bearings, thrust bearing races, a pivot bolt and a pivotnut.

In some embodiments there is a flexible rod that runs under the boardmembers along the long axis the length of both board members and isattached at one end to the rear fork member and the other end at thefront fork member

In some embodiments the board member is constructed of 13 ply birchwhich gives it great stiffness and can support the pivot point.

In some embodiments the board member is constructed of differentmaterial.

DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will become moreevident upon reading the following description of the preferredembodiment in conjunction with the accompanying drawings, in which:

FIG. 1 is a prior art side view of a skateboard.

FIG. 2 shows the skateboard of FIG. 1 as seen from the underside.

FIG. 3 is a prior art side view of a mountain board.

FIG. 4 shows the mountain board of FIG. 3 as seen from the underside.

FIG. 5 is a prior art view of a skateboard having two wheels in tandem.

FIG. 6 shows the skateboard of FIG. 5 as seen from the underside.

FIG. 7 is a side view of the present invention.

FIG. 8 shows the present invention of FIG. 7 as seen from the underside.

FIG. 9 shows the present invention of FIG. 7 as seen from the top.

FIG. 10 is a side view of a portion of the present invention whichdetails the pivot point.

FIG. 11 is a side view of a user riding the current invention during thepower stroke where the user obtains forward motion from contact of theuser's foot and the ground.

FIG. 12 is a side view of a user riding the current invention whilecoasting where the user's feet are positioned perpendicular to the longaxis of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 and FIG. 2 illustrates a prior art skateboard device 10. In FIG.1 and FIG. 2 the board member 11 is supported from below by four wheels12, 14, 20 and 22. Wheels 12 and 20 are connected together by axle 24.Wheels 14 and 22 are connected together by axle 26. Axle 24 is connectedto the board 11 by truck 16. Axle 26 is connected to the board 11 bytruck 18.

FIG. 3 and FIG. 4 illustrates a prior art mountain board device 28. InFIG. 3 and FIG. 4 the board member 29 is supported from below by fourwheels 30, 32, 34 and 36. Wheels 30 and 34 are connected together byaxle 38. Wheels 32 and 36 are connected together by axle 40. Axle 38 isconnected to the board 29 by truck 42. Axle 40 is connected to the board29 by truck 44.

FIG. 5 and FIG. 6 illustrates a prior art skateboard device 46. In FIG.5 and FIG. 6 the board member 47 is supported by a rear wheels 48 and afront wheel 50. Rear wheels 48 extends through the board member 47through opening 53 and is attached to the board member 47 at axle 52.The front wheel 50 is connected to the board 47 by fork 54 connected atpivot 56 which is forward of front wheel 50. Pivot 56 allows fork 54 andwheel 50 to move perpendicular to the axis through pivot 56. Wheel 50 iscentered with axis perpendicular to the long axis of the board 47 byspring 58 which connects at one end to the rear of fork 54 and at theother end to board 47 at attachment point 60. A user riding this boardcan affect a change of direction by shifting his/her weight on theboard. Under weight shifting conditions the fork 54 and front wheel 50moves perpendicular to the axis at pivot 56. This motion is much like acaster on a shopping cart. The spring 56 dampens and governs the motion.When the user's weight is more directly centered along the long axis ofboard 47, the axis of wheel 50 will return to a position perpendicularto the long axis of board 47.

FIG. 7, FIG. 8 and FIG. 9 illustrates the current invention 68. In FIG.7, FIG. 8 and FIG. 9 the rear board member 69 is supported from theground by wheel 72. The rear wheel 72 extends to the rear of boardmember 69 and extends above the level of board member 69. The frontboard member 70 is supported from the ground by wheel 74. The frontwheel 74 extends to the front of board member 70 and extends above thelevel of board member 70.

The rear board member 69 is attached to the front board member 70 atpivot point 84. The front wheel 74 is attached to fork member 78 atconnection points 75 and 77 and extends under the front of board member70 and connects with board member 70 at 82. The rear wheel 72 isattached to fork member 76 at connection points 73 and 89 and extendsunder the rear of board member 69 and connects with board member 69 at80.

A flexible member 86 connects the rear of front fork 76 a with the frontof rear fork 78.

The user places one foot on rear board member 69 with that foot orientedabout 45 degrees relative to the major axis of the device and ispropelled forward by the user pushing against the ground with his/herother foot. This motion is much like the typical means of propelling askateboard forward. The flexible member 86 gives the invention a falsecenter which keeps the major axes of each board member in alignment evenwhen the user's foot is not on either board member.

Once the user has achieved a satisfactory rate of speed from this means,the user can place the other foot on the front board member 70 orientingeach foot in a direction perpendicular to the long axis of the device.With both feet oriented perpendicular to the major axis of both boardmembers 69 and 70, the user has more control over the invention and canaffect a change in direction by moving the front and rear board memberaround the pivot point 84 with the user's feet. The user's weight andfeet motion can overcome the centering force of the flexible member 86.

FIG. 10 is a side view of a portion of the present invention whichdetails the pivot point. In FIG. 10 the pivot bolt 100 extends throughfront board member 94 and rear board member 98 and is visible as 102. Aheavy gauge washer 104 spreads the load of pivot bolt 100. Pivot bolt100 also passes through thrust bearing 106, top thrust bearing race 108and bottom thrust bearing race 110. Pivot bolt 100 also passes throughthrust bearing 112, top thrust bearing race 114 and bottom thrustbearing race 116. Pivot bolt 100 is secured against bottom thrustbearing race 116 by nut 118. When pivot bolt 100 is secured by nut 118,rear board member 98 and front board member 94 are free to rotate aroundpivot bolt 100. Industrial strength thrust bearings and bearing racesallow rear board member 98 and front board member 94 to rotate aroundpivot bolt 100 irrespective of the downward pressure of the userstanding on the device.

FIG. 11 and FIG. 12 are descriptions of the current invention 134 beingridden by user 138.

In FIG. 11 the user 138 is in the power stroke where the user isobtaining forward motion by moving his/her right foot 140 against theground 142. The user's left foot 144 rests on the rear board member 136.While this description describes the user's left foot remaining on theboard while driving off the ground with the user's right foot; theopposite arrangement is also possible.

In FIG. 12 the user has gained sufficient forward motion and is nowcoasting. The user 138 has repositioned his/her feet 140 and 144 to aposition pointing perpendicular to the long axis of the invention 134.The user's left foot 140 is on the rear board member 136 and the user'sright foot 144 is on the front board member 146. The user 138 can nowaffect direction changes of the invention 134 by changing theorientation of his/her feet relative to each other without liftingeither foot off the invention. Moving the user's feet inward withhis/her toes being closer than his/her heels causes the device to moveto the left. Moving the user's feet outward with his/her toes beingfarther apart than his/her heels causes the device to move to the right.

I claim:
 1. An articulated two wheeled board comprising: a front horizontal planar board member; a rear horizontal planar board member; a front fork assembly having a rearward end rigidly connected to a forward end of the front board member and a pair of fork members extending forwardly and upwardly from the forward end of the front board member; a rear fork assembly having a forward end rigidly connected to a rearward end of the rear board member and a pair of fork members extending rearwardly and upwardly from the rearward end of the rear board member; a single front wheel rotatably supported between the pair of fork members of the front fork assembly; a single rear wheel rotatably supported between the pair of fork members of the rear fork assembly; a pivot connection for connecting a rearward end of the front board member to a forward end of the rear board member for permitting pivotal movement therebetween about a vertical axis while maintaining the front and rear board members in a substantially parallel relationship; and a flexible member extending below the front and rear board members for maintaining the front and rear wheels in a longitudinally aligned orientation, the flexible member having a forward end connected to the rearward end of the front fork assembly and a rearward end connected to the forward end of the rear fork assembly.
 2. The articulated two wheeled board according to claim 1, wherein the pivot connection includes a pivot bolt, two thrust bearings, and a nut.
 3. The articulated two wheeled board according to claim 2 wherein the pivot connection further includes four thrust bearing races. 